What is it about?
When scientists fire powerful laser pulses at ultra-thin plastic foils, they can generate high-speed proton beams with potential applications in cancer therapy, materials science, and more. However, fluctuations in proton energy and output often limit practical use. In this study, we conducted nearly 1,000 shots to identify key factors affecting stability. We found that the thickness of the plastic foil and precise laser focusing are critical: foils that are too thin or misaligned laser spots cause unstable proton beams. Small laser fluctuations, like unwanted "pre-pulses," also disrupt acceleration. By controlling foil thickness within an optimal range (e.g., around 600 nanometers) and adjusting the laser’s focus position, we achieved significantly more stable proton beams. This work provides practical guidelines for building reliable laser-driven proton accelerators. By refining these parameters, future systems could deliver stable, high-energy proton beams for real-world applications, such as precise cancer treatments or advanced material research, bridging the gap between lab breakthroughs and everyday use.
Featured Image
Photo by Dynamic Wang on Unsplash
Why is it important?
This work uniquely combines high-volume experimental data (971 shots) with real-time diagnostics to pinpoint critical factors affecting proton beam stability—a major roadblock for medical and industrial applications. By identifying target thickness and laser focus as key control parameters, we provide actionable guidelines for stabilizing laser-driven accelerators, directly addressing the growing demand for reliable high-repetition-rate systems. Our findings bridge lab-scale breakthroughs to real-world viability, offering timely insights for researchers advancing next-generation laser technologies.
Perspectives
We initially wanted to find out the core variables that affect proton acceleration by real-time monitoring of dozens of parameters such as lasers and target materials, just like "decoding". However, the experimental data revealed a complex world: many factors are intertwined and cannot be simply attributed. It was finally found that under specific experimental conditions (such as target thickness of 600 nanometers ± 10%, precise fine-tuning of laser focus), proton energy will be output stably. This seemingly limited discovery is crucial - it is like an "operation map" that guides engineers to optimize equipment within a controllable range and avoid blind trial and error. For example, a stable proton beam is required in medical applications, and our research provides a direct basis for locking key control parameters. Although the variable network in reality is far more complex than imagined, it is this effort to anchor key nodes in chaos that drives laboratory technology to take a solid step towards practical application.
Ying Gao
Peking University
Read the Original
This page is a summary of: Hunting for sources of variability in laser-proton acceleration with thin foils, Physics of Plasmas, April 2025, American Institute of Physics,
DOI: 10.1063/5.0246173.
You can read the full text:
Contributors
The following have contributed to this page
